The present invention relates to the field of semiconductor devices of the type having a lateral drift region and a conducting field plate, and more particularly to provide such a semiconductor device integrally adapted for sensing and analysis of instantaneous and time-variable output voltage from source to drain.
All electrical devices are capable of operating at a defined maximum voltage. Exceeding the rated maximum voltage results in an electrical breakdown, or possibly total destruction of the device. Semiconductor devices are similarly voltage sensitive. In previously known circuits in which a semiconductor device, e.g. a transistor, is subject to a high voltage, an external component was added to the circuit to detect the voltage. Connection of this external component to a controller allowed the voltage to be disconnected before the transistor was harmed. Of course, the addition of an external component involves added labor and expense.
The present invention recognizes that the semiconductor device itself can be configured to incorporate a separated field plate circuit for the determination of excess voltage, eliminating the need to add an external component for this purpose. The invention disclosed herein provides a modified SOI-LDMOS semiconductor device for enabling the detection of an output voltage between the source and drain of the device. The field plate of the device is isolated and divided into two or more sub-field plates, each of which has an external contact electrode. A first added circuit for detection and measurement of the instantaneous voltage is connected to a first of the electrodes and a second circuit for detection of the voltage over time is connected to a second of the electrodes.
Therefore, the invention disclosed below provides a semiconductor device comprising an isolated field plate that is split into a plurality of sub-field plates, each having a terminal connection area for sensing and analysis of voltage values therefrom, and an external analytical circuit.